Anisotropic transverse magnetoresistivity in alpha-YbAlB4

TL;DR

This study investigates the anisotropic transverse magnetoresistivity in alpha-YbAlB4, revealing field-dependent behavior and suppression of heavy fermion characteristics at specific magnetic field strengths.

Contribution

It provides the first detailed measurement of anisotropic transverse magnetoresistivity in alpha-YbAlB4, highlighting the directional dependence and field-induced suppression of heavy fermion behavior.

Findings

Magnetoresistivity is highly anisotropic.

Negative magnetoresistivity observed above 3 T along c-axis.

Heavy fermion behavior suppressed around 5.5 T.

Abstract

We measured the transverse magnetoresistivity of the mixed valence compound $\alpha$-YbAlB$_4$. Two configurations were used where current was applied along [110] direction for both and magnetic field was applied along [-110] and $c$-axis. We found the transverse magnetoresistivity is highly anisotropic. In the weak field below 1 T, it is consistent with stronger $c$-$f$ hybridization in the $ab$ plane which was suggested from the previous zero field resistivity measurements. At the higher field above 3 T, we observed a negative transverse magnetoresistivity for the field applied along the $c$-axis. The temperature dependences of the resistivity measured at several different fields suggest the suppression of the heavy fermion behavior at the characteristic field of $\sim 5.5$ T.